// Arduino Mega2560(16MHz), 256KB Flash, 8KB SRAM, 4KB EEPROM
// Timer0(8)....CKscf(400kHz)...OC0A
// Timer1(16)...ADATE(50us)...OCR1B
// Timer2(8)....LCD timing
// Timer5(16)...LEDout, EXTout
#define DAF 0
#define RAF 1
#define FAF 2
#define DTF1 3
#define DTF2 4
#define DTF3 5
#define M 400
#define N 3100
#define Fs 10000
#define Ft1 50
#define Ft2 100
#define Ft3 200
#define NG 20
#define MUTE 500
#include <avr/pgmspace.h>

PROGMEM prog_uint8_t dB[]={255,40,35, 30, 25, 20, 15,  10,   5,   0};
PROGMEM prog_uint16_t Mag[]={0,41,73,129,230,410,728,1295,2303,4095};
volatile uint8_t swcntr;
uint8_t Ef, G, G0, Gf, MODE=0, admux=0;
uint32_t S;
int16_t X[N], E, E0, P, Pmax, R, Fa, Q, Qmax, mute=MUTE;

#include "aafxlib.h"

void setup(){
	uint8_t tmp;
	DDRB=0x17;	PORTB=0x01;	// xxxoxooo
	DDRC=0x3f;	PORTC=0x00;	// xxoooooo
	DDRD=0x7f;	PORTD=0x80;	// rooooooo
	DDRL=0x18;	PORTL=0x00;	// xxxooxxx
	TCCR0A=0x00;TCCR0B=0x03;// WGM0=000, CS0=011(CK/32)
	TCCR2A=0x42;TCCR2B=0x01;// COM2A=01, WGM2=010(CTC/OCRA), CS2=001(CK/1)
	OCR2A=20;				// CKscf=400kHz
	TCCR1A=0x00;TCCR1B=0x09;// WGM1=0100(CTC), CS1=001(CK/1)
	OCR1A=OCR1B=799;		// 50us
	TCCR5A=0xa3;TCCR5B=0x09;// WGM5=0111(10bit FastPWM), CS5=001(CK/1)
	ADCSRA=0xad;			// ADEN=1, ADATE=1, ADIE=1,ADPS=110(ADCK/32)
	ADCSRB=0x05;			// if(TCNT1==OCR1B) ADC start
	ADMUX=0xe0;				// REFS=11(2.56V), ADLAR=1, MUX=000000(CH0)
	SPCR=0x50;	SPSR=0x00;	// SPE=1,DORD=0,MSTR=1,CPOL=0,CPHA=0,SPR=00(fck/4)
	tmp=SPSR;	tmp=SPDR;
	TIMSK0&=~(1<<TOIE0);
	lcdinit();	Ef=1;	Gf=1;
}
void loop(){
	if(swcntr>0){						// SWオンなら
		P=0;
		if(++MODE>DTF3)	MODE=DAF;		// DAF→RAF→FAF→DTF1→DTF2→DTF3...
		while(swcntr>0);				// SWオフを待つ
		E0=~E;	R=0;	S=0;	P=0;	mute=MUTE;
	}
	if(Ef){	mute=MUTE;	lcdfbk();	Ef=0;	}
	if(Gf){	mute=MUTE;	lcddb(G);	Gf=0;	}
}
//	admux ... 00(E) → 01(A) → 10(G) → 11(A)
ISR(ADC_vect){							// ADC complete(50us)
	uint8_t A, w1;
	int16_t A16,b;
	int32_t x1, x2;
	TIFR1|=0x06;						// clear OCF1B, OCF1A
	A16=ADCL; A16=((uint16_t)(A=ADCH)<<2)+(A16>>6);	//000000dddddddddd(0〜1023)
	if(admux & 0x01){					// 01 or 11 ... 100us
		ADMUX=(admux&0x02)?0xe0:0xe1;	// 次はCH0/CH1
		if(MODE==DAF){					// *** DAF/DVF ***
			daout10(X[P]);				// Pmaxサンプル前のデータを出力
			X[P]=A16;
			if(++P>=Pmax)	P=0;
		}else if(MODE==RAF){			// *** RAF/RVF ***
			if(R==0)	daout12(A16<<2);
			else{
				b=((int32_t)((A16<<2)-2048)*(100-R)+(int32_t)X[P]*R)/100; //b:-2048..2047
				daout12(b+2048);	X[P]=b;
				if(++P>=500)	P=0;
			}
		}else if(MODE==FAF){			// *** FAF ***
			if(Fa==0)	daout12(A16<<2);
			else{
				P+=(uint16_t)M/(Fs/Fa);
				if(P>=M)	P-=M;
				daout12(((int32_t)pgm_read_byte(&W[P])-128)*(A16-512)/32+2047);
										//		-128..127	-512..511
			}
		}else if(MODE>=DTF1){			// *** DTF1..3 ***
			w1=pgm_read_byte(&W[R]);	// 0..255
			x1=X[P];	x2=X[(P<Pmax-1)?(P+1):0];	// 0..M
			daout12(((x1*(255-w1)+x2*w1)*pgm_read_byte(&W[Q]))>>12);// 0..M*2
			A16-=512; if(A16<0) A16=-A16;	// A16: 0..512
			S+=A16;						// S: 0..512*M/2
			if(++R>=M/2){				// 矩形窓で絶対値のM/2個の平均を計算
				X[P]=(S>>8);			// 0..M
				if(++P>=Pmax)	P=0;
				R=0;	S=0;
			}
			Q+=((MODE==DTF1)?(M/(Fs/Ft1)):(MODE==DTF2)?(M/(Fs/Ft2)):(M/(Fs/Ft3)));
			if(Q>=M) Q-=M;				// W[]のポインタ(FtにするQのステップ)
		}
	}else if(admux & 0x02){				// 10	val of A1(VR)...0..255
		ADMUX=0xe2;						// 次はCH2
		G=(uint16_t)A*10/256;			// G: 0..9
		dbout(pgm_read_word(&Mag[G]));
		if(G!=G0){	Gf=1;	G0=G;	}
	}else{								// 00
		ADMUX=0xe2;						// 次はCH2
		if(MODE==DAF)		E=Pmax=(uint16_t)(A>>3)*100;// E,Pmax:0,100,..,3100
		else if(MODE==RAF)	E=R =(uint16_t)A*8/256*10;	// E,R:  0,10,20,...,70
		else if(MODE==FAF)	E=Fa=(uint16_t)A*11/256*50;	// E,Fa: 0,50,...,500
		else if(MODE>=DTF1) E=Pmax=(A>>3)+2;			// E,Pmax: 2..33
		if(E!=E0){	Ef=1;	E0=E;	}
	}
	admux++;
	if((PIND&0x80)==0)	swcntr=200;
	else if(swcntr>0)	swcntr--;
}